860 THE MUSCLES. 



extremity. One of these branches, thin and pale, is prolonged to near the internal condyle of 

 the femur, while the principal stops, as in the Horse, on the posterior face of the bone. 



The adductor parvus is scarcely distinct from the adductor magnus. The latter is undivided 

 at its inferior extremity, which stops at the posterior face of the femur, without going to the 

 inner condyle of that bone. 



The obturator intemus has no upper portion; it is united to the obturator externus in 

 passing through the obturator foramen. 



B Pig. In this animal, the internal crural muscles offer somewhat the same arrangement 



as in the Ox. 



C. Carnivora. — In the Dog and Cat, tlie sartorius arises from the external angle of the 

 ilium, and by its muscular portion is prolonged to the inner face of the tibia. The gracilis is 

 much thinner and narrower than in the other animals. The adductor parvus is a little, distinct 

 muscle, which begins on the inferior face of the pubis, and terminates at the posterior face of 

 the femur, below the quadratus femoris. The adductor magnus is, on the contrary, a wide, 

 thick, undivided muscle, attached to nearly the whole extent of the linea aspera of the femur. 



There is nothing particular to note with regard to the quadratus femoris and the obturators; 

 the gemelli are always composed of two small, distinct fasciculi, which comport themselves as 

 in Man. 



Comparison of the Muscles of Man's Thigh with those of the Thigh op Animals. 

 The muscles of the thigh in Man are divided into three regions, as in animals. 



1. Anteeior Muscles. 



The rectus parvus is not found in Man; nevertheless, there are reckoned three anterior 

 muscles of the thigh, because the sartorius, which corresponds to the sartorius of animals, is 

 included in this region. 



The sartorius is a very long muscle, the width of which at most is about two fingers' 

 breadth. It is attached above, not to the lumbo-iliac aponeurosis, but to the anterior and 

 superior iliac spine; it is afterwards directed downwards and inwards, to pass round the 

 internal condyle of the femur, and terminate by an expanding tendon at the crest of the tibia. 



The tensor of the fascia lata shows the same general arrangement observed in animals. It 

 is the same with the triceps femoris. The rectus femoris arises by two tendinous branches: one 

 is detached from the anterior and inferior iliac spine; the other from the brim of the cotyloid 

 cavity. 



2. Muscles of the Posterior Region. 



These are three in number : the femoral or crural biceps, semitendinosus, and semimembranosus. 



The biceps femoris is represented in 8olipeds by the posterior portion of the biceps femoris. It 

 is an elongated muscle arising by two heads : tlie long head comes from the ischiatic tuberosity ; 

 the shortest from tlie middle of the linea aspera. After their union, these two heads give rise 

 to a tendon which is fixed into the head of the fibula, and sends an expansion over the tibial 

 aponeurosis. 



The semitendinosus arises in common with the long head of the biceps ; its inferior tendon 

 lis reflected beneath the internal tuberosity of the tibia, to be fixed into the crest of that bone. 

 This tendon, with that of the sartorius, forms the aponeurotic expansion called the goose's foot. 



The semimembranosus is voluminous in its lower portion, and arises, like the other two, 

 from the tuberosity of the ischium; its fibres pass to a tendon which, on reaching the inner 

 Bide of the knee, terminates in the three pieces composing that articulation (see Fig. 200). 



3. Muscles of the Internal Region. 



In books on human anatomy, these muscles are snmetimes designated, from their action, by 

 the generic name of adductors. They comprise : the internal rectus, peftineus. first or middle 

 adductor, second or small adductor, and third or great adductor. The square crural, the 

 obturators, and the gemelli are described among the posterior muscles of the pelvis. They 

 will, however, be briefly alluded to liere. 



The internal rectus corresponds to the gracilis of animals. It is a thin muscle, bordering 

 the inner side of the thigh. It is attached, above, to the symphysis pubis ; below, to the crest 

 of the tibia, in common with the sartorius tendon. 



